The U.S. stock market almost wiped out his retirement account, but retired pilot Ronald Scarpa hasn't lost his taste for risk. Lately he has turned to one of the chanciest investments in the world - the Iraqi dinar.

In the words of popular comedian Ron White, "You can't fix stupid." That phrase, as elegant in its simplicity as it is frankly true, applies with special fervor to those who continue to believe that they are about to make millions, billions, or...